In semiconductor manufacturing, ion implantation is a common technique for altering properties of semiconductor wafers during the production of various semiconductor-based products. Ion implantation may be used to introduce conductivity-altering impurities (e.g., dopant implants), to modify crystal surfaces (e.g., pre-amorphization), to created buried layers (e.g., halo implants), to create gettering sites for contaminants, and to create diffusion barriers (e.g., fluorine and carbon co-implant). Also, ion implantation may be used in non-transistor applications such as for alloying metal contact areas, in flat panel display manufacturing, and in other surface treatment. All of these ion implantation applications may be classified, generally, as forming a region of material property modification.
Ion extraction systems often include an ion source having an arc chamber, a source housing, and suppression and ground electrodes. An extraction aperture is positioned adjacent the ion source, and the source body, an arc chamber base and the arc chamber are loosely assembled together, wherein the extraction aperture is a part of the arc chamber. In this configuration, the extraction aperture may shift as much as +/−1.5 mm following, for example, routine maintenance to the ion extraction system. As a result, beam setup parameters of each beam-line component need to be adjusted to compensate for the shift of the extraction aperture, causing beam transport loss in addition to increasing the beam tuning time. Unfortunately, both a beam tuning time increase and a beam transport loss reduces the production throughput of the ion extraction system.
Furthermore, conventional ion extraction systems may produce an appendix arc outside the arc chamber as a by-product of the filament, the arc voltage, and the bias voltage present. This appendix arc is not sustainable to the extraction, and exists in a periodic manner. As a result, the ion beam extracted from the appendix arc exits the source housing and damages the suppression and ground electrodes adjacent the source housing, causing ion beam glitches. The ion beam glitches negatively impact beam extraction stability and beam current of the ion extraction system.